The internet likes an ever-expanding knowledge base, and people may find answers in the internet. However, currently, there is lack of satisfied means for users to conveniently access static information stored in thousands of servers. Certainly, search engines can be used for querying information, but users have to express their questions in a machine apprehensible way, for example a question is divided into a logic combination of a plurality of keywords. However, it is difficult to accurately describe the information to be obtained, and it is hard for users to obtain the most desired results.
Compared with the internet-linked machines, millions of human brains communicating through the internet can better satisfy users' knowledge seeking demands. Human brains can comprehend natural languages without any difficulty, and what's more the scale of a knowledge base comprised by the experiences and memories of millions of human beings is beyond measure. That is the reason why the mutual aid question-answer services on the internet are generally popular. People can ask to anyone on the other end of the internet for any questions about medical, science, entertainment, emotion, and so on, and they can usually obtain pointed answers.
However, the existing online mutual aid question-answer system has many shortcomings at present. Firstly, the user who can answer the question is not online all the time so that questions are difficult to answer in time; secondly, questioning user and answering user need to browse a certain web page from time to time to know whether a question is answered, or whether there is a question to be answered; moreover, answering user can only use a finite number of ways to express their answers, such as words or pictures, and can not communicate directly.